Ammunition



Feb. 1, 1944. STEVENSON 2,340,284

AMMUNITION Filed June -7, 1940 Ill 111;

W 1 imam ill-WW2 IQLWS I 11192111: u-r- Thoma-5 Stevenson.

' Att c: rue 5 Patented Feb. 1, 1944 UNITED STATES PATENT OFFICEAMMUNITION Thomas Stevenson, Philadelphia, Pa.

Application June '7, 1940, Serial No. 339,321

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3700. G. 757) 3 Claims.

The invention described herein may be manufactured and used by or forthe Government for governmental purposes without the payment to me or"any royalty thereon.

This invention relates to ammunition and more particularly it hasreference to a method of and an arrangement for protecting the primercomposition from the volatile materials in a propellent charge.

Modern smokeless powder used as propellants in ammunition containvarious volatile substances and the particular efiect they have on thepriming composition will depend on the ingredients of the composition.For example, if the primer is of the potassium chlorate type containingin addition lead sulfocyanide and trinitrotoluene and the propellentcharge is a double base powder containing nitroglycerine, the primerwill gradually become desensitized by the nitroglycerine vapor.

Although the chemical reactions which occur are not thoroughlyunderstood in all cases, it is an established fact that certainvolatiles from propellent powders will act deleteriously on certainpriming compositions. Some of the other volatiles commonly found inpropellent powder are dinitrotoluene, diphenylamine, ethyl alcohol,ethyl ether, acetone and water.

The purpose of this invention is to provide a sealing disk between thepriming composition and the propellent charge and to convenientlyassemble it by employing the primer cup as a punch.

The specific nature of the invention as well as other objects andadvantages thereof will clearly appear from a description of a preferredembodiment as shown in the accompanying drawing in which:

Figs. 1 to 4 are fragmentary longitudinal sectional views showing thesteps in assembling a primer to a cartridge case and cutting out thesealing disk.

Referring to the drawing by characters of reference there is shown aportion of a cartridge case 5 having a recess 6 and a flash passage 7which leads from the recess to the interior of the case in which thepropellent charge is carried.

The primer is of conventional type and comprises a cup 8 containing inits closed end a priming composition 9 covered by a sealing disk H]. Ananvil l I inserted in the cup is formed with the usual vents l2 and itsbase l3 protrudes partly beyond the rim of the cup in a well knownmanner.

A strip M of a sealing material which may for example be a syntheticplastic, impregnated paper or textile, or metal foil is placed over theouter face of the cartridge case and spans the recess 6 as seen inFig. 1. When the primer, which is to serve as a punch during itsinsertion into the recess, approaches the mouth of the recess, theprojecting portion of the base of anvil engages the strip of sealingmaterial and exerts a downward pressure which stretches the material ofthe strip as indicated in Fig. 2, and 01T- sets a circular disk portion[5 within the mouth or" the cup. The cup 8 is now in position to enterthe recess and its outer rim cooperates with the rim of the recess toshear the sealing material. The punched out disk is then forced into therecess as seen in Fig. 3 and when the primer is fully home the disk isheld on the floor of the recess and effectively closes the flash passageI. The distortion of the material during the punching operation providesan outwardly or rearwardly turned marginal portion which snugly fits theside Wall of the recess and covers the joint between the cup and theanvil.

I claim:

1. The method of sealing the flash passage in a primer recess of acartridge case which comprises interposing a strip of sealing materialover the mouth of the recess, simultaneously compressin and stretchingthe material at the mouth of the recess on a peripheral line of slightlyless diameter than that of the recess to a degree short of rupturing thematerial, then shearing the material at the rim of the recess andadvancing the sheared disk to the bottom of the recess, whereby asealing disk with upturned periphery is produced.

2. The method of sealing the vents of ammunition primers having a cupand anvil and adapted to be inserted into a cavity in an ammunition caseprovided with a flash opening, comprising interposing a sheet of sealingmaterial between the primer cup and anvil, and said cavity, advancingthe anvil against the sheet throughout an area of less diameter than thecavity to depress the material into the cavity and simultaneouslyadvancing the primer cup to shear the material at the rim of saidcavity, whereby a sealing disk with upturned periphery is produced, andfurther advancing the cup, anvil and disk to the bottom of theammunition case cavity, to seal the anvil vents and flash opening insaid cavity.

3. The method of sealing the vents of ammunition primers having a cupand anvil and adapted to be inserted into a cavity in an ammunition caseprovided with a flash opening, comprising placing the anvil in the cupwith a portion thereof extending below the bottom of the cup,interposing a sheet of sealing material between the primer cup andanvil, and said cavity, advancing the anvil against the sheet throughoutan area of less diameter than said cavity to depress the material intothe cavity, and simultaneously advancing the primer cup to shear thematerial at the rim of the cavity whereby a sealing disk with upturnedperiphery is produced, and further advancing the cup, anvil and disk, tothe bottom of the ammunition case cavity to seal the anvil vents andflash opening in said cavity.

THOMAS STEVENSON.

